The present invention relates generally to digital communication systems and more particularly to a wireless digital communication system.
The use of low cost, portable, short haul high speed data transmission equipment has significant data collection advantages when observing and evaluating scientific data in real time from remote locations. This is especially desirable when processing analog inputs, which are digitally transformed in real time, such as digital signal processing (DSP) signals. This type of data collection often requires fast computational analysis, and immediate conversion back to real time for proper evaluation. Often data is taken at remote locations, such as antenna ranges or mobile sites, where the computing or DSP equipment cannot be co-located with the data collection equipment and thereby a portable data relay must be incorporated to satisfy the data collection requirements.
High speed data transfer has traditionally been achieved via fiber optic land lines or elaborate microwave relay links. Fiber optic systems require a substantial investment in equipment and cable routing and are not portable. Fiber optic systems also require alteration to the landscape in order to bury a cable, which is often forbidden in certain areas. At a minimum burying a cable presents a major inconvenience.
Traditional microwave links are relatively expensive and require bulky antennas and transceivers, which do not easily adapt to a mobile environment. RF data transfer above 50 Mb/s require a substantially higher carrier frequency than the data rate itself, which almost always requires the use of microwave and millimeter wave frequencies. In addition, most microwave links require the data to be pre-processed by elaborate modulators prior to transmission. A similar elaborate demodulation process must also take place at the receiver. Consequently, most applications cannot afford the complexity of a microwave link.
The present invention is therefore directed to the problem of developing a wireless digital communications system that is portable, easily installed in the field, relatively inexpensive and transfers a high data rate.